Grain boundary segregation in Ni-base (718 plus) superalloy

Segregation of phosphorus and molybdenum to grain boundaries in a commercial grade Ni-base (718 plus) superalloy subjected to different heat treatments has been examined using a field emission gun scanning transmission electron microscope with energy dispersive X-ray microanalysis. The results indicate that P and Mo concentrations at grain boundaries increase in linear manner with the square root of aging time.